Dynamic healthchecking load balancing gateway

ABSTRACT

A method for providing a dynamic healthchecking gateway is provided. The method may include receiving an application request. The method may also include determining if a plurality of load balancing information is available for the application request. The method may further include in response to determining that a plurality of load balancing information is not available for the application request, registering the requested application in a repository. The method may include monitoring the availability of a plurality of servers and the availability of the requested application. The method may additionally include determining an available runtime instance based on the monitoring. The method may also include forwarding the received application request to the determined available runtime instance.

BACKGROUND

The present invention relates generally to the field of computers, andmore particularly to load balancing.

Within a solution architecture it is common practice to deploy anapplication to multiple instances of a runtime to provide scalabilityand high availability. Each runtime will normally include a number ofapplications, each providing their own capability. Normally a loadbalancing component will be used to distribute traffic across theavailable instances.

SUMMARY

According to one embodiment, a method for providing a dynamichealthchecking gateway is provided. The method may include receiving anapplication request. The method may also include determining if aplurality of load balancing information is available for the applicationrequest. The method may further include in response to determining thata plurality of load balancing information is not available for theapplication request, registering the requested application in arepository. The method may include monitoring the availability of aplurality of servers and the availability of the requested application.The method may additionally include determining an available runtimeinstance based on the monitoring. The method may also include forwardingthe received application request to the determined available runtimeinstance.

According to another embodiment, a computer system for providing adynamic healthchecking gateway is provided. The computer system mayinclude one or more processors, one or more computer-readable memories,one or more computer-readable tangible storage devices, and programinstructions stored on at least one of the one or more storage devicesfor execution by at least one of the one or more processors via at leastone of the one or more memories, whereby the computer system is capableof performing a method. The method may include receiving an applicationrequest. The method may also include determining if a plurality of loadbalancing information is available for the application request. Themethod may further include in response to determining that a pluralityof load balancing information is not available for the applicationrequest, registering the requested application in a repository. Themethod may include monitoring the availability of a plurality of serversand the availability of the requested application. The method mayadditionally include determining an available runtime instance based onthe monitoring. The method may also include forwarding the receivedapplication request to the determined available runtime instance.

According to yet another embodiment, a computer program product forproviding a dynamic healthchecking gateway is provided. The computerprogram product may include one or more computer-readable storagedevices and program instructions stored on at least one of the one ormore tangible storage devices, the program instructions executable by aprocessor. The computer program product may include program instructionsto receive an application request. The computer program product may alsoinclude program instructions to determine if a plurality of loadbalancing information is available for the application request. Thecomputer program product may further include in response to determiningthat a plurality of load balancing information is not available for theapplication request, program instructions to register the requestedapplication in a repository. The computer program product may includeprogram instructions to monitor the availability of a plurality ofservers and the availability of the requested application. The computerprogram product may additionally include program instructions todetermine an available runtime instance based on the monitoring. Thecomputer program product may also include program instructions toforward the received application request to the determined availableruntime instance.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

These and other objects, features and advantages of the presentinvention will become apparent from the following detailed descriptionof illustrative embodiments thereof, which is to be read in connectionwith the accompanying drawings. The various features of the drawings arenot to scale as the illustrations are for clarity in facilitating oneskilled in the art in understanding the invention in conjunction withthe detailed description. In the drawings:

FIG. 1 illustrates a networked computer environment according to atleast one embodiment;

FIG. 2 illustrates an exemplary system architecture according to atleast one embodiment;

FIG. 3 is an operational flowchart illustrating the steps carried out bya program that that provides a dynamic healthchecking gateway accordingto at least one embodiment;

FIG. 4 is a block diagram of internal and external components ofcomputers and servers depicted in FIG. 1 according to at least oneembodiment;

FIG. 5 is a block diagram of an illustrative cloud computing environmentincluding the computer system depicted in FIG. 1, according to at leastone embodiment; and

FIG. 6 is a block diagram of functional layers of the illustrative cloudcomputing environment of FIG. 5, according to at least one embodiment.

DETAILED DESCRIPTION

Detailed embodiments of the claimed structures and methods are disclosedherein; however, it can be understood that the disclosed embodiments aremerely illustrative of the claimed structures and methods that may beembodied in various forms. This invention may, however, be embodied inmany different forms and should not be construed as limited to theexemplary embodiments set forth herein. Rather, these exemplaryembodiments are provided so that this disclosure will be thorough andcomplete and will fully convey the scope of this invention to thoseskilled in the art. In the description, details of well-known featuresand techniques may be omitted to avoid unnecessarily obscuring thepresented embodiments.

Embodiments of the present invention relate generally to the field ofcomputers, and more particularly to load balancing. The followingdescribed exemplary embodiments provide a system, method and programproduct to, among other things, provide a dynamic healthcheckinggateway. Therefore, the present embodiment has the capacity to improvethe technical field of load balancing by providing gateway loadbalancing capability with application level healthchecking. As such, thepresent embodiment provides the benefits of application load balancingwith the configuration and administration of the gateway load balancer.

As previously described, it is common practice within a solutionarchitecture to deploy an application to multiple instances of a runtimeto provide scalability and high availability. Each runtime will normallyinclude a number of applications, each providing their own capability.Normally a load balancing component will be used to distribute trafficacross the available instances.

Currently, the approach to load balancing is twofold. First, anapplication level configuration may be created in which a configurationfor each application to load balance is created. As such, each availableruntime instance and healthcheck configuration may be set up. Normallythe healthcheck will be configured at the application level using a HTTPHEAD requests or a similar approach, to assure that the application isavailable on that runtime instance.

Secondly, a Gateway is provided for a number of applications running onthe runtime instances. This Gateway is configured with the runtimeinstances and healthchecks configuration is set up. The healthcheck willbe at the runtime instance level to verify that the entire server isavailable.

The Gateway approach has the benefit that it handles all applicationrequests, however it does not allow for the situation where a singleapplication is unavailable while the server is still available. Theapplication level healthcheck overcomes this issue, but it requiresconfiguration for each application. As such, it may be advantageous,among other things, to provide the benefits of application loadbalancing with the configuration and administration of the gateway loadbalancer.

According to at least one implementation, the present embodiment mayprovide the ability of the Gateway Load Balancer to create dynamicapplication based health checking, without it being configured by theadministrator on an application by application basis. As such, thegateway load balancer will learn and manage the applications that it isload balancing for, and automatically create the required healthchecking.

Therefore, the present embodiment may provide gateway load balancingcapability with application level healthchecking. As such, the presentembodiment may provide the benefits of application load balancing withthe configuration and administration of a Gateway Load Balancer.

The present invention may be a system, a method, and/or a computerprogram product. The computer program product may include a computerreadable storage medium (or media) having computer readable programinstructions thereon for causing a processor to carry out aspects of thepresent invention.

The computer readable storage medium can be a tangible device that canretain and store instructions for use by an instruction executiondevice. The computer readable storage medium may be, for example, but isnot limited to, an electronic storage device, a magnetic storage device,an optical storage device, an electromagnetic storage device, asemiconductor storage device, or any suitable combination of theforegoing. A non-exhaustive list of more specific examples of thecomputer readable storage medium includes the following: a portablecomputer diskette, a hard disk, a random access memory (RAM), aread-only memory (ROM), an erasable programmable read-only memory (EPROMor Flash memory), a static random access memory (SRAM), a portablecompact disc read-only memory (CD-ROM), a digital versatile disk (DVD),a memory stick, a floppy disk, a mechanically encoded device such aspunch-cards or raised structures in a groove having instructionsrecorded thereon, and any suitable combination of the foregoing. Acomputer readable storage medium, as used herein, is not to be construedas being transitory signals per se, such as radio waves or other freelypropagating electromagnetic waves, electromagnetic waves propagatingthrough a waveguide or other transmission media (e.g., light pulsespassing through a fiber-optic cable), or electrical signals transmittedthrough a wire.

Computer readable program instructions described herein can bedownloaded to respective computing/processing devices from a computerreadable storage medium or to an external computer or external storagedevice via a network, for example, the Internet, a local area network, awide area network and/or a wireless network. The network may comprisecopper transmission cables, optical transmission fibers, wirelesstransmission, routers, firewalls, switches, gateway computers and/oredge servers. A network adapter card or network interface in eachcomputing/processing device receives computer readable programinstructions from the network and forwards the computer readable programinstructions for storage in a computer readable storage medium withinthe respective computing/processing device.

Computer readable program instructions for carrying out operations ofthe present invention may be assembler instructions,instruction-set-architecture (ISA) instructions, machine instructions,machine dependent instructions, microcode, firmware instructions,state-setting data, or either source code or object code written in anycombination of one or more programming languages, including an objectoriented programming language such as Smalltalk, C++ or the like, andconventional procedural programming languages, such as the “C”programming language or similar programming languages. The computerreadable program instructions may execute entirely on the user'scomputer, partly on the user's computer, as a stand-alone softwarepackage, partly on the user's computer and partly on a remote computeror entirely on the remote computer or server. In the latter scenario,the remote computer may be connected to the user's computer through anytype of network, including a local area network (LAN) or a wide areanetwork (WAN), or the connection may be made to an external computer(for example, through the Internet using an Internet Service Provider).In some embodiments, electronic circuitry including, for example,programmable logic circuitry, field-programmable gate arrays (FPGA), orprogrammable logic arrays (PLA) may execute the computer readableprogram instructions by utilizing state information of the computerreadable program instructions to personalize the electronic circuitry,in order to perform aspects of the present invention.

Aspects of the present invention are described herein with reference toflowchart illustrations and/or block diagrams of methods, apparatus(systems), and computer program products according to embodiments of theinvention. It will be understood that each block of the flowchartillustrations and/or block diagrams, and combinations of blocks in theflowchart illustrations and/or block diagrams, can be implemented bycomputer readable program instructions.

These computer readable program instructions may be provided to aprocessor of a general purpose computer, special purpose computer, orother programmable data processing apparatus to produce a machine, suchthat the instructions, which execute via the processor of the computeror other programmable data processing apparatus, create means forimplementing the functions/acts specified in the flowchart and/or blockdiagram block or blocks. These computer readable program instructionsmay also be stored in a computer readable storage medium that can directa computer, a programmable data processing apparatus, and/or otherdevices to function in a particular manner, such that the computerreadable storage medium having instructions stored therein comprises anarticle of manufacture including instructions which implement aspects ofthe function/act specified in the flowchart and/or block diagram blockor blocks.

The computer readable program instructions may also be loaded onto acomputer, other programmable data processing apparatus, or other deviceto cause a series of operational steps to be performed on the computer,other programmable apparatus or other device to produce a computerimplemented process, such that the instructions which execute on thecomputer, other programmable apparatus, or other device implement thefunctions/acts specified in the flowchart and/or block diagram block orblocks.

The flowchart and block diagrams in the Figures illustrate thearchitecture, functionality, and operation of possible implementationsof systems, methods, and computer program products according to variousembodiments of the present invention. In this regard, each block in theflowchart or block diagrams may represent a module, segment, or portionof instructions, which comprises one or more executable instructions forimplementing the specified logical function(s). In some alternativeimplementations, the functions noted in the block may occur out of theorder noted in the figures. For example, two blocks shown in successionmay, in fact, be executed substantially concurrently, or the blocks maysometimes be executed in the reverse order, depending upon thefunctionality involved. It will also be noted that each block of theblock diagrams and/or flowchart illustration, and combinations of blocksin the block diagrams and/or flowchart illustration, can be implementedby special purpose hardware-based systems that perform the specifiedfunctions or acts or carry out combinations of special purpose hardwareand computer instructions.

The following described exemplary embodiments provide a system, methodand program product for a dynamic healthchecking load balancing gateway.According to at least one implementation, the present embodiment has thecapacity to provide the capability for a Gateway Load Balancer toprovide dynamic application based health checking by dynamicallybuilding and enabling the health check configuration of applicationsusing a gateway. More specifically, the present embodiment maydynamically check the health of applications deployed to a server byextracting the endpoint from the request message. As such, if a newapplication is installed, no configuration would be required to enablethe health check. Therefore, the health check may be enabled on a newlyadded application with no additional action required from a user.

Referring to FIG. 1, an exemplary networked computer environment 100 inaccordance with one embodiment is depicted. The networked computerenvironment 100 may include a computer 102, a processor 104, and a datastorage device 106 that is enabled to run a software program 108 and aHealthchecking Load Balancing Gateway Program 116A. The networkedcomputer environment 100 may also include a server 114 that is enabledto run a Healthchecking Load Balancing Gateway Program 116B that mayinteract with a database 112 and a communication network 110. Thenetworked computer environment 100 may include a plurality of computers102 and servers 114, only one of which is shown. The communicationnetwork may include various types of communication networks, such as awide area network (WAN), local area network (LAN), a telecommunicationnetwork, a wireless network, a public switched network and/or asatellite network. It should be appreciated that FIG. 1 provides only anillustration of one implementation and does not imply any limitationswith regard to the environments in which different embodiments may beimplemented. Many modifications to the depicted environments may be madebased on design and implementation requirements.

The client computer 102 may communicate with the Healthchecking LoadBalancing Gateway Program 116B running on server computer 114 via thecommunications network 110. The communications network 110 may includeconnections, such as wire, wireless communication links, or fiber opticcables. As will be discussed with reference to FIG. 4, server computer114 may include internal components 800 a and external components 900 a,respectively, and client computer 102 may include internal components800 b and external components 900 b, respectively. Server computer 114may also operate in a cloud computing service model, such as Software asa Service (SaaS), Platform as a Service (PaaS), or Infrastructure as aService (IaaS). Server 114 may also be located in a cloud computingdeployment model, such as a private cloud, community cloud, publiccloud, or hybrid cloud. Client computer 102 may be, for example, amobile device, a telephone, a personal digital assistant, a netbook, alaptop computer, a tablet computer, a desktop computer, or any type ofcomputing devices capable of running a program, accessing a network, andaccessing a database 112. According to various implementations of thepresent embodiment, the Healthchecking Load Balancing Gateway Program116A, 116B may interact with a database 112 that may be embedded invarious storage devices, such as, but not limited to a computer 102, anetworked server 114, or a cloud storage service.

As previously described, the client computer 102 may access theHealthchecking Load Balancing Gateway Program 116B, running on servercomputer 114 via the communications network 110. For example theHealthchecking Load Balancing Gateway Program 116A, 116B running on aclient computer 102 may provide the ability of the Gateway Load Balancerto create dynamic application based health checking, without it beingconfigured by the administrator on an application by application basis.As such, the Gateway Load Balancer may learn and manage the applicationsthat it is load balancing for, and automatically create the requiredhealth checking. The Healthchecking Load Balancing Gateway method mayinclude a gateway load balancer, an availability store (i.e., arepository, such as database 112), and a health checking component. TheHealthchecking Load Balancing Gateway method is explained in more detailbelow with respect to FIGS. 2-3.

Referring now to FIG. 2, an exemplary system architecture 200 inaccordance with one embodiment is depicted. According to at least oneimplementation, the Gateway Load Balancer 202 may be configured with theavailable runtime instances. The server healthcheck (TCP portavailability) and application level health check methods; such as HTTPHEAD requests may also be defined. This information will be storedwithin the Availability Store 204. At this stage the Health CheckingComponent 206 may start monitoring the availability of the runtimeinstances. With respect to FIG. 2, this corresponds to ServerA 102 andServerB 114. According to at least one implementation, when the GatewayLoad Balancer 202 receives a request, (i.e., an application request) itwill verify if load balancing information is available for thisapplication (e.g., Application 1 210); based on the target URL. However,as this is the first request, it will not be found. Then, theApplication 1 210 will be registered within the Availability Store 204and the Health Checking Component 206 will then start monitoring theavailability of the servers and Application 1 210.

The Gateway Load Balancer 202 will then forward the request to theavailable runtime instance. In the case of the initial request this maybe before or after the first Application 1 210 health check depending onthe configuration of the system. For example, the Gateway Load Balancer202 may be configured to wait until the Health Checking Component 206has verified that the application 210, 212 is available beforeforwarding or decide to be forwarded based on the server availabilityinformation. Additionally, The Gateway Load Balancer 202 also records inthe Availability Store 204 the last time a request was sent to anapplication 210, 212.

Significantly, the Health Checking Component 206 is now monitoring theServerA 102 and also Application 1 210. As such, if Application 1 210 isdisabled on ServerA 102, but the ServerA 102 itself remains available,either deliberately or due to a failure, the Health Checking Component206 will identify the issue and update the Availability Store 204 withthe corresponding information. However, if the entire ServerA 102 isunavailable, then all services on that ServerA 102 will be marked asunavailable. The building up of the applications being load balancedwill continue and could be persisted to assure the information isretained.

In an alternate embodiment, an extension may be to remove an application210, 212 from the healthchecking logic if an application request has notbeen received over a certain period of time. As such, a HousekeepingComponent 208 may be configured to periodically check the AvailabilityStore 204 and remove entries which have not been used for a set time(time period also configurable and may be pre-determined). Therefore,old entries may be stopped from building up in the Availability Store204 and as a result may improve performance.

Referring now to FIG. 3, an operational flowchart 300 illustrating thesteps carried out by a program that provides a dynamic healthcheckinggateway in accordance with one embodiment is depicted. As previouslydescribed, the Gateway Load Balancer 202 (FIG. 2) may be configured withthe available runtime instances and the server healthcheck (TCP portavailability) and application level health check method, such as HTTPHEAD requests may also be defined and stored within the AvailabilityStore 204 (FIG. 2).

With respect to FIG. 3 at 302, the Gateway Load Balancer 202 (FIG. 2)receives an application request. Then at 304, the Gateway Load Balancer202 (FIG. 2) will verify if load balancing information is available forthe requested application.

Therefore, at 306, it is determined whether there is load balancinginformation available for the requested application. According to atleast one implementation, the verification, may be based on the targetURL. If at 306 it is determined that there is no load balancinginformation available for the requested application, then the method maycontinue to step 312 to register the requested application request withthe Availability Store 204 (FIG. 2). For example, if this is the firstrequest, the requested application will not be found and therefore, theapplication will be registered within the Availability Store 204 (FIG.2). Next at 308, the Health Checking Component 206 (FIG. 2) will beginmonitoring the availability of the servers and the requestedapplication.

If at 306 it is determined that there is load balancing informationavailable for the requested application, then the method will proceeddirectly to step 308 where the Health

Checking Component 206 (FIG. 2) will begin monitoring the availabilityof the servers and the requested application.

Next, at 310, the Gateway Load Balancer 202 (FIG. 2) will forward therequest to the available runtime instance. According to at least oneimplementation and in the case of the initial request this may occurbefore or after the first application health check depending on theconfiguration of the system. For example, the Gateway Load Balancer 202(FIG. 2) may be configured to wait until the Health Checking Component206 (FIG. 2) has verified that the requested application is availablebefore forwarding or decide to be forwarded based on the serveravailability information. Additionally, The Gateway Load Balancer 202(FIG. 2) may also record in the Availability Store 204 (FIG. 2) the lasttime a request was sent to an application.

Significantly, and as previously described, the Health CheckingComponent 206 (FIG. 2) begins monitoring the ServerA 102 (FIG. 2) andalso the requested application. Therefore, if an application is disabledon a ServerA 102 (FIG. 2), but the ServerA 102 (FIG. 2) itself remainsavailable, either deliberately or due to a failure, the Health CheckingComponent 206 (FIG. 2) will identify the issue and update theAvailability Store 204 (FIG. 2) with the corresponding information.However, if the entire ServerA 102(FIG. 2) is unavailable, then allservices on that ServerA 102 (FIG. 2) will be marked as unavailable.According to the present embodiment, the building up of the applicationsbeing load balanced will continue and could be persisted to assure theinformation is retained.

It may be appreciated that FIGS. 2-3 provide only an illustration of oneimplementation and does not imply any limitations with regard to howdifferent embodiments may be implemented. Many modifications to thedepicted environments may be made based on design and implementationrequirements. As previously mentioned, in an alternate embodiment, anextension may be to remove an application from the healthchecking logicif an application request has not been received over a certain period oftime. As such, a Housekeeping Component 208 (FIG. 2) may be configuredto periodically check the Availability Store 204 (FIG. 2) and removeentries which have not been used for a set time (time period alsoconfigurable and may be pre-determined). Therefore, old entries may bestopped from building up in the Availability Store 204 (FIG. 2) and as aresult may improve performance.

According to various implementations, the present embodiment does notrequire individual application health check configuration. Additionally,new applications may be automatically health checked if a request ismade for its endpoint. Furthermore, health checks can be automaticallydisabled based on the history of usage for a particular endpoint.Significantly, the present embodiments provides the capability for aGateway Load Balancer 202 (FIG. 2) to provide dynamic application basedhealth checking.

FIG. 4 is a block diagram 400 of internal and external components ofcomputers depicted in FIG. 1 in accordance with an illustrativeembodiment of the present invention. It should be appreciated that FIG.4 provides only an illustration of one implementation and does not implyany limitations with regard to the environments in which differentembodiments may be implemented. Many modifications to the depictedenvironments may be made based on design and implementationrequirements.

Data processing system 800, 900 is representative of any electronicdevice capable of executing machine-readable program instructions. Dataprocessing system 800, 900 may be representative of a smart phone, acomputer system, PDA, or other electronic devices. Examples of computingsystems, environments, and/or configurations that may be represented bydata processing system 800, 900 include, but are not limited to,personal computer systems, server computer systems, thin clients, thickclients, hand-held or laptop devices, multiprocessor systems,microprocessor-based systems, network PCs, minicomputer systems, anddistributed cloud computing environments that include any of the abovesystems or devices.

User client computer 102 (FIG. 1) and network server 114 (FIG. 1) mayinclude respective sets of internal components 800 a,b and externalcomponents 900 a,b illustrated in FIG. 4. Each of the sets of internalcomponents 800 include one or more processors 820, one or morecomputer-readable RAMs 822 and one or more computer-readable ROMs 824 onone or more buses 826, and one or more operating systems 828 and one ormore computer-readable tangible storage devices 830. The one or moreoperating systems 828 and the Software Program 108 (FIG. 1) and theHealthchecking Load Balancing Gateway Program 116A (FIG. 1) in clientcomputer 102 (FIG. 1) and the Healthchecking Load Balancing GatewayProgram 116B (FIG. 1) in network server 114 (FIG. 1) are stored on oneor more of the respective computer-readable tangible storage devices 830for execution by one or more of the respective processors 820 via one ormore of the respective RAMs 822 (which typically include cache memory).In the embodiment illustrated in FIG. 4, each of the computer-readabletangible storage devices 830 is a magnetic disk storage device of aninternal hard drive. Alternatively, each of the computer-readabletangible storage devices 830 is a semiconductor storage device such asROM 824, EPROM, flash memory or any other computer-readable tangiblestorage device that can store a computer program and digitalinformation.

Each set of internal components 800 a,b also includes a R/W drive orinterface 832 to read from and write to one or more portablecomputer-readable tangible storage devices 936 such as a CD-ROM, DVD,memory stick, magnetic tape, magnetic disk, optical disk orsemiconductor storage device. A software program, such as the SoftwareProgram 108 (FIG. 1) and the Healthchecking Load Balancing GatewayProgram 116A, 116B (FIG. 1) can be stored on one or more of therespective portable computer-readable tangible storage devices 936, readvia the respective R/W drive or interface 832 and loaded into therespective hard drive 830.

Each set of internal components 800 a,b also includes network adaptersor interfaces 836 such as a TCP/IP adapter cards, wireless Wi-Fiinterface cards, or 3G or 4G wireless interface cards or other wired orwireless communication links. The Software Program 108 (FIG. 1) and theHealthchecking Load Balancing Gateway Program 116A (FIG. 1) in clientcomputer 102 (FIG. 1) and the Healthchecking Load Balancing GatewayProgram 116B (FIG. 1) in network server 114 (FIG. 1) can be downloadedto client computer 102 (FIG. 1) and network server 114 (FIG. 1) from anexternal computer via a network (for example, the Internet, a local areanetwork or other, wide area network) and respective network adapters orinterfaces 836. From the network adapters or interfaces 836, theSoftware Program 108 (FIG. 1) and the Healthchecking Load BalancingGateway Program 116A (FIG. 1) in client computer 102 (FIG. 1) and theHealthchecking Load Balancing Gateway Program 116B (FIG. 1) in networkserver 114 (FIG. 1) are loaded into the respective hard drive 830. Thenetwork may comprise copper wires, optical fibers, wirelesstransmission, routers, firewalls, switches, gateway computers and/oredge servers.

Each of the sets of external components 900 a,b can include a computerdisplay monitor 920, a keyboard 930, and a computer mouse 934. Externalcomponents 900 a,b can also include touch screens, virtual keyboards,touch pads, pointing devices, and other human interface devices. Each ofthe sets of internal components 800 a,b also includes device drivers 840to interface to computer display monitor 920, keyboard 930 and computermouse 934. The device drivers 840, R/W drive or interface 832 andnetwork adapter or interface 836 comprise hardware and software (storedin storage device 830 and/or ROM 824).

It is understood in advance that although this disclosure includes adetailed description on cloud computing, implementation of the teachingsrecited herein are not limited to a cloud computing environment. Rather,embodiments of the present invention are capable of being implemented inconjunction with any other type of computing environment now known orlater developed.

Cloud computing is a model of service delivery for enabling convenient,on-demand network access to a shared pool of configurable computingresources (e.g. networks, network bandwidth, servers, processing,memory, storage, applications, virtual machines, and services) that canbe rapidly provisioned and released with minimal management effort orinteraction with a provider of the service. This cloud model may includeat least five characteristics, at least three service models, and atleast four deployment models.

Characteristics are as follows:

On-demand self-service: a cloud consumer can unilaterally provisioncomputing capabilities, such as server time and network storage, asneeded automatically without requiring human interaction with theservice's provider.

Broad network access: capabilities are available over a network andaccessed through standard mechanisms that promote use by heterogeneousthin or thick client platforms (e.g., mobile phones, laptops, and PDAs).

Resource pooling: the provider's computing resources are pooled to servemultiple consumers using a multi-tenant model, with different physicaland virtual resources dynamically assigned and reassigned according todemand. There is a sense of location independence in that the consumergenerally has no control or knowledge over the exact location of theprovided resources but may be able to specify location at a higher levelof abstraction (e.g., country, state, or datacenter).

Rapid elasticity: capabilities can be rapidly and elasticallyprovisioned, in some cases automatically, to quickly scale out andrapidly released to quickly scale in. To the consumer, the capabilitiesavailable for provisioning often appear to be unlimited and can bepurchased in any quantity at any time.

Measured service: cloud systems automatically control and optimizeresource use by leveraging a metering capability at some level ofabstraction appropriate to the type of service (e.g., storage,processing, bandwidth, and active user accounts). Resource usage can bemonitored, controlled, and reported providing transparency for both theprovider and consumer of the utilized service.

Service Models are as follows:

Software as a Service (SaaS): the capability provided to the consumer isto use the provider's applications running on a cloud infrastructure.The applications are accessible from various client devices through athin client interface such as a web browser (e.g., web-based e-mail).The consumer does not manage or control the underlying cloudinfrastructure including network, servers, operating systems, storage,or even individual application capabilities, with the possible exceptionof limited user-specific application configuration settings.

Platform as a Service (PaaS): the capability provided to the consumer isto deploy onto the cloud infrastructure consumer-created or acquiredapplications created using programming languages and tools supported bythe provider. The consumer does not manage or control the underlyingcloud infrastructure including networks, servers, operating systems, orstorage, but has control over the deployed applications and possiblyapplication hosting environment configurations.

Infrastructure as a Service (IaaS): the capability provided to theconsumer is to provision processing, storage, networks, and otherfundamental computing resources where the consumer is able to deploy andrun arbitrary software, which can include operating systems andapplications. The consumer does not manage or control the underlyingcloud infrastructure but has control over operating systems, storage,deployed applications, and possibly limited control of select networkingcomponents (e.g., host firewalls).

Deployment Models are as follows:

Private cloud: the cloud infrastructure is operated solely for anorganization. It may be managed by the organization or a third party andmay exist on-premises or off-premises.

Community cloud: the cloud infrastructure is shared by severalorganizations and supports a specific community that has shared concerns(e.g., mission, security requirements, policy, and complianceconsiderations). It may be managed by the organizations or a third partyand may exist on-premises or off-premises.

Public cloud: the cloud infrastructure is made available to the generalpublic or a large industry group and is owned by an organization sellingcloud services.

Hybrid cloud: the cloud infrastructure is a composition of two or moreclouds (private, community, or public) that remain unique entities butare bound together by standardized or proprietary technology thatenables data and application portability (e.g., cloud bursting forload-balancing between clouds).

A cloud computing environment is service oriented with a focus onstatelessness, low coupling, modularity, and semantic interoperability.At the heart of cloud computing is an infrastructure comprising anetwork of interconnected nodes.

Referring now to FIG. 5, illustrative cloud computing environment 500 isdepicted. As shown, cloud computing environment 500 comprises one ormore cloud computing nodes 100 with which local computing devices usedby cloud consumers, such as, for example, personal digital assistant(PDA) or cellular telephone 500A, desktop computer 500B, laptop computer500C, and/or automobile computer system 500N may communicate. Nodes 100may communicate with one another. They may be grouped (not shown)physically or virtually, in one or more networks, such as Private,Community, Public, or Hybrid clouds as described hereinabove, or acombination thereof. This allows cloud computing environment 500 tooffer infrastructure, platforms and/or software as services for which acloud consumer does not need to maintain resources on a local computingdevice. It is understood that the types of computing devices 500A-Nshown in FIG. 5 are intended to be illustrative only and that computingnodes 100 and cloud computing environment 500 can communicate with anytype of computerized device over any type of network and/or networkaddressable connection (e.g., using a web browser).

Referring now to FIG. 6, a set of functional abstraction layers 600provided by cloud computing environment 500 (FIG. 5) is shown. It shouldbe understood in advance that the components, layers, and functionsshown in FIG. 6 are intended to be illustrative only and embodiments ofthe invention are not limited thereto. As depicted, the following layersand corresponding functions are provided:

Hardware and software layer 60 includes hardware and softwarecomponents. Examples of hardware components include: mainframes 61; RISC(Reduced Instruction Set Computer) architecture based servers 62;servers 63; blade servers 64; storage devices 65; and networks andnetworking components 66. In some embodiments, software componentsinclude network application server software 67 and database software 68.

Virtualization layer 70 provides an abstraction layer from which thefollowing examples of virtual entities may be provided: virtual servers71; virtual storage 72; virtual networks 73, including virtual privatenetworks; virtual applications and operating systems 74; and virtualclients 75.

In one example, management layer 80 may provide the functions describedbelow. Resource provisioning 81 provides dynamic procurement ofcomputing resources and other resources that are utilized to performtasks within the cloud computing environment. Metering and Pricing 82provide cost tracking as resources are utilized within the cloudcomputing environment, and billing or invoicing for consumption of theseresources. In one example, these resources may comprise applicationsoftware licenses. Security provides identity verification for cloudconsumers and tasks, as well as protection for data and other resources.User portal 83 provides access to the cloud computing environment forconsumers and system administrators. Service level management 84provides cloud computing resource allocation and management such thatrequired service levels are met. Service Level Agreement (SLA) planningand fulfillment 85 provide pre-arrangement for, and procurement of,cloud computing resources for which a future requirement is anticipatedin accordance with an SLA.

Workloads layer 90 provides examples of functionality for which thecloud computing environment may be utilized. Examples of workloads andfunctions which may be provided from this layer include: mapping andnavigation 91; software development and lifecycle management 92; virtualclassroom education delivery 93; data analytics processing 94;transaction processing 95; and Healthchecking Load Balancing Gateway 96.A Healthchecking Load Balancing Gateway Program 116A, 116B (FIG. 1) mayprovide a dynamic healthchecking load balancing gateway.

The descriptions of the various embodiments of the present inventionhave been presented for purposes of illustration, but are not intendedto be exhaustive or limited to the embodiments disclosed. Manymodifications and variations will be apparent to those of ordinary skillin the art without departing from the scope of the describedembodiments. The terminology used herein was chosen to best explain theprinciples of the embodiments, the practical application or technicalimprovement over technologies found in the marketplace, or to enableothers of ordinary skill in the art to understand the embodimentsdisclosed herein.

What is claimed is:
 1. A processor-implemented method for providing adynamic healthchecking gateway, the method comprising: receiving, by aprocessor, an application request; determining if a plurality of loadbalancing information is available for the application request; inresponse to determining that a plurality of load balancing informationis not available for the application request, registering the requestedapplication in a repository; monitoring the availability of a pluralityof servers and the availability of the requested application;determining an available runtime instance based on the monitoring; andforwarding the received application request to the determined availableruntime instance.
 2. The method of claim 1, wherein the determining ifthe plurality of load balancing information is available for theapplication request is based on a target URL.
 3. The method of claim 1,further comprising: recording a last time a request was sent to anapplication.
 4. The method of claim 3, wherein the last time a requestwas sent to the application is recorded in the repository.
 5. The methodof claim 1, further comprising: identifying a plurality of informationassociated with the availability of each server within the monitoredplurality of servers.
 6. The method of claim 5, further comprising:recording the identified plurality of information associated with theavailability of each server within the monitored plurality of servers inthe repository.
 7. The method of claim 1 further comprising: determiningif an entire server within the monitored plurality of servers isunavailable; and marking all services associated with the determinedentire server as unavailable in the repository.
 8. The method of claim 1further comprising: removing a plurality of entries from the repositorybased on a request for an application not being received during apre-determined time period.
 9. A computer system for providing a dynamichealthchecking gateway, the computer system comprising: one or moreprocessors, one or more computer-readable memories, one or morecomputer-readable tangible storage devices, and program instructionsstored on at least one of the one or more storage devices for executionby at least one of the one or more processors via at least one of theone or more memories, wherein the computer system is capable ofperforming a method comprising: receiving, by a processor, anapplication request; determining if a plurality of load balancinginformation is available for the application request; in response todetermining that a plurality of load balancing information is notavailable for the application request, registering the requestedapplication in a repository; monitoring the availability of a pluralityof servers and the availability of the requested application;determining an available runtime instance based on the monitoring; andforwarding the received application request to the determined availableruntime instance.
 10. The computer system of claim 9, wherein thedetermining if the plurality of load balancing information is availablefor the application request is based on a target URL.
 11. The computersystem of claim 9, further comprising: recording a last time a requestwas sent to an application.
 12. The computer system of claim 11, whereinthe last time a request was sent to the application is recorded in therepository.
 13. The computer system of claim 9, further comprising:identifying a plurality of information associated with the availabilityof each server within the monitored plurality of servers.
 14. Thecomputer system of claim 13, further comprising: recording theidentified plurality of information associated with the availability ofeach server within the monitored plurality of servers in the repository.15. The computer system of claim 9, further comprising: determining ifan entire server within the monitored plurality of servers isunavailable; and marking all services associated with the determinedentire server as unavailable in the repository.
 16. The computer systemof claim 9 further comprising: removing a plurality of entries from therepository based on a request for an application not being receivedduring a pre-determined time period.
 17. A computer program product forproviding a dynamic healthchecking gateway, the computer program productcomprising: one or more computer-readable storage devices and programinstructions stored on at least one of the one or more tangible storagedevices, the program instructions executable by a processor, the programinstructions comprising: program instructions to receive, by aprocessor, an application request; program instructions to determine ifa plurality of load balancing information is available for theapplication request; in response to determining that a plurality of loadbalancing information is not available for the application request,program instructions to register the requested application in arepository; program instructions to monitor the availability of aplurality of servers and the availability of the requested application;program instructions to determine an available runtime instance based onthe monitoring; and program instructions to forward the receivedapplication request to the determined available runtime instance. 18.The computer program product of claim 17, wherein the determining if theplurality of load balancing information is available for the applicationrequest is based on a target URL.
 19. The computer program product ofclaim 17, further comprising: program instructions to record a last timea request was sent to an application.
 20. The computer program productof claim 19, wherein the last time a request was sent to the applicationis recorded in the repository.